Canon EF 28-300mm f/3.5-5.6 L IS USM - Some Canon EF lenses incorporate an image stabiliser to prevent camera shake from spoiling the shot. This is particularly useful on close-ups or at slow shutter speeds, in situations where a tripod camera cannot be used. Optical shake is detected by gyro sensors which provide data to neutralise the shake. Some EF lenses have two IS modes, including one for panned shots to help you enjoy still greater photographic freedom.